The invention relates to a method and a device for operating a photovoltaic (PV) system having a plurality of photovoltaic modules and a first and a second DC motor connected to the photovoltaic modules, wherein the DC motors are or can be coupled to a three-phase generator, wherein the three-phase generator can be connected to a power grid, and wherein the electric energy supplied by a photovoltaic modules can be distributed to the to DC motors in any selected arrangement.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
A device of this type has been described in prior U.S. application Ser. No. 12/649,536, filed Dec. 30, 2009, entitled “METHOD FOR OPERATING A PHOTOVOLTAIC SYSTEM AND PHOTOVOLTAIC SYSTEM FOR CARRYING OUT THE METHOD” by the same applicant, which is incorporated herein by reference. Supply contracts with associated energy providers frequently require that the solar power plants are designed to supply to the power grid an agreed-upon minimum power within a determined time interval. For example, a 2.4 MW solar power plant may be required to supply between 11 AM and 5 PM at least 60% of the rated power, meaning about 1.5 MW. Depending on the weather, this minimum power cannot always be generated by the solar system alone.
It would therefore be desirable and advantageous to provide an improved method and a device for operating a solar power plant which obviate prior art shortcomings and are capable of supplying the required minimum power level at any time.